Abstract

Apple snails (Pomacea paludosa) and eggs and nestlings of anhingas (Anhinga anhinga) and white ibises (Eudocimus albus) were collected in Palm Beach County, Florida from 1989–1991 and analyzed for organochlorine pesticide (OCP) residues. Pesticide residues were not detected in the apple snails. Residues of DDT, with maximum concentrations of 1,200 μg/kg wet weight occurred in 50% of the ibis samples but were not present in the anhinga samples. DDE occurred in 100% of avian samples at concentrations up to 2,100 μg/kg and was at significantly greater concentration in the anhingas. Dieldrin was not detected in the first year of the three-year study, but occurred in the majority of avian samples in the last two years at concentrations up to 610 μg/kg. Additionally, residues of seven pesticides and Aroclor® 1016 were detected infrequently at very low concentrations in the birds. While it is possible that nearby municipal solid waste landfills were the source of the pesticides, no corroborating evidence was found to support this speculation.

Spalding MG, Forrester DJ (1991) Effects of parasitism and disease on the nesting success of colonial wading birds (Ciconiiformes) in southern Florida. Final report to the Florida Game and Fresh Water Fish Commission, December 1991, Tallahassee, FL